What should i know before buying a linux pc

What should i know before buying a linux pc?

Hardly any software works on it and if you don't understand source code then forget getting linux, i used it for a few months and it was a waste of time, don't bother, go for windows xp, not vista, yet. forget what people tell you about linux being better than windows, it isnt, those people just want to be different and probably like the smell of their own foeces